A Great Treat Or Daily Diet For Goldfish, Certain Reptiles and Tropical Fish, Discus, Smaller Freshwater Fishes, Turtles and Some Lizards. Bio-Pure FD is the worlds cleanest freeze-dried fish food available today. Pharmaceutical freeze-drying techniques allow us to give you a product as close to fresh as humanly possible. Expect a texture and taste not previously available in a freeze-dried food.